What was the title of the CSI series finale?

The CSI series finale was titled "Immortality." This two-hour finale originally aired on CBS on September 27, 2015, bringing the long-running Las Vegas crime drama to a close.

Written by series creator Anthony E. Zuiker and directed by Louis Shaw Milito, "Immortality" begins with a suicide bombing at the Eclipse casino. The investigation brings Catherine Willows back from Los Angeles and reunites several important characters from the show's history, including Gil Grissom, Sara Sidle, and Jim Brass.

The title is sometimes confused with "The End Game," which was the title of the fifteenth season's final regular episode. "Immortality" followed that episode as a feature-length conclusion and served as the actual series finale. It also helped resolve several character arcs rather than ending with a routine standalone case.

The finale closes with Sara hearing Grissom confess his love for her and sailing away with him from San Diego. The episode therefore functions both as a crime story and as a farewell to the original team's central relationships.